Friday, November 23, 2012

The Cisco Application Control Engine (ACE) is a device for doing server loadbalancing, distributing to load of a service to multiple hosts.
Here is a short example configuration for loadbalancing on two servers running a webserver.

First we configure the addresses to the realservers, this is the actual servers that will process the requests.

Next we are creating a serverfarm with our two servers that will handle this service and make it use the probe we created.host1/Admin(config)# serverfarm SERVERFARM-WEBSERVERShost1/Admin(config-sfarm-host)# probe WEBPROBEhost1/Admin(config-sfarm-host)# rserver SERVER1host1/Admin(config-sfarm-host-rs)# inservicehost1/Admin(config-sfarm-host)# rserver SERVER2host1/Admin(config-sfarm-host-rs)# inservice

Thats all that you need.We now have a probe trying to connect to port 80 on the two servers, as soon as the servers are starting to reply to the http requests with code 200 (OK) then the loadbalancer will put the VIP online and start relaying all incoming traffic on interface vlan 120 towards the VIP to the both realservers using round-robin.

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The Best Practice Blog is maintained by Markus Klock, a Cisco-certified computer networks consultant and Svante Boberg, a Senior server operations engineer.Here we write about computer networks, virtualization, security and other tech suff.